Cooling upgrades

[Lenz]

Lenz, where do you live? I have 3 like new SS flex fans, all with different pitches, that I tried on my '70 Stang. I switched long ago to a an OEM type thermo clutch fan and love it for both cooling and low sound. All 3 fans were loud at cruising speeds of say 2,300-2,400 rpm, this over the sound of a worked near 500HP 358 Windsor with Flowmasters!  I'd be glad to ship them to you for a try if you'd like as they will (and are) just collecting dust in garage and they will not go back on the car.

Thanks for the offer Bob, but I know I would not like the racket they put up, got a brother in law with one in a chebbie and it's near all you can hear.  The original fan worked with my tired 390, but neither it or the Summit piece I've got in there now get it done with the 445.  That whole Countour fan setup sounds like a decent cost effective winter diversion project, I'm sure we've got some in our local boneyards.  I have plenty of room between the radiator and pump pulley, think that's the route I'll try.

[Falcon67]

... dual flex-a-lite fans rated at 1100cfms and draw 8 amps, pushing and mounted in front of radiator.

IMHO, that is part of your issue.  Pusher fans are WAY less efficient than pullers.  Also, they do a good job of blocking air through the radiator, especially on the wind side of it.  Those spinning blades turn into circles of cardboard at speed.  Note this factory style electric fan shroud and the  large ports specifically there to bleed off pressure building up on the front side.



Also, 1100 CFM isn't anywhere close to what you probably need.  Another thing to keep in mind for aluminum - hotter is better.  180 is marginal, 195 better.  OEM cars with aluminum radiators, ever see a 170 or 180 thermostat in one?  No, 200+.  Also, a tight fin count on a copper brass setup reduces the effectiveness of each additional core.  So you need more pull - a LOT more fan pull - to go from a 3 core brass unit to a 4 core than you'd need for a dual 1" core aluminum unit. 

[Falcon67]

... dual flex-a-lite fans rated at 1100cfms and draw 8 amps, pushing and mounted in front of radiator.

IMHO, that is part of your issue.  Pusher fans are WAY less efficient than pullers.  Also, they do a good job of blocking air through the radiator, especially on the wind side of it.  Those spinning blades turn into circles of cardboard at speed.  Note this factory style electric fan shroud and the  large ports specifically there to bleed off pressure building up on the front side.



Also, 1100 CFM isn't anywhere close to what you probably need.  Another thing to keep in mind for aluminum - hotter is better.  180 is marginal, 195 better.  OEM cars with aluminum radiators, ever see a 170 or 180 thermostat in one?  No, 200+.  If you want a cool motor, you need to heat up the working fluid.  Also, a tight fin count on a copper brass setup reduces the effectiveness of each additional core.  So you need more pull - a LOT more fan pull - to go from a 3 core brass unit to a 4 core than you'd need for a dual 1" core aluminum unit.

[Drew Pojedinec]

Doug,
Any opinion on one of my threads is always appreciated.
As far as aluminum vs copper/brass/stock radiator, I agree with you on a technical level, tho it's a moot point right now.  The car came with an aluminum radiator and I don't think I'm going to change it unless given no other option.

Chris, I completely agree with you on the pusher vs puller point of view.  I'm still on the fence  regarding making the jump to the other side of the radiator.  I really love the clean look of having the fans hidden.
I'm not concerned whatsoever about them blocking air tho as I have zero issues with cooling at any speed other than idle.
The 1100cfm is for each fan.  I tend to think that flex-a-lite was a little liberal with their rating tho.  As stated the previous engine which was MUCH tamer was on the edge of too hot with this setup.

When I get home (Friday-Saturday) I'll let ya all know what worked as I'm going to change one thing at a time.

[cjshaker]

Just to add to what I mentioned before, I don't think a lower thermostat would help. If your car is getting hot, the thermostat will be full open, assuming it is working properly.

Just for the sake of the conversation, a friends Jeep with a basically stock SBC transplant had overheating issues. It had Flex-a-Lite fans on it. They were replaced with a good Spal unit and that was enough to cure it.

But a flex fan, especially a big one, eats up lots of otherwise free hp!

http://www.network54.com/Forum/215655/message/1066184641/Car+Craft+Cooling+Fan+Dyno+Test

About 12-15 horsepower, according to that article and the fan I'm using. I don't want an electric fan on my car, and I think the clutch fans are ugly. And since it's my car....

[Stangman]

Everybody has there own preferences and what works on someones car may not work on another they say theres an ass for every seat

[FElony]

Deleted

[Stangman]

Felony that's perfect is that NOS

[Joey120373]

That rear end is kinda epic......


I am kind of an electronics guy, wondering about the 3 relays...
As Jay pointed out, most of the "standard" or "unoversal" relays have 2 contacts, one provides a path for current when the relay is off, the other provides a path for current when the relay is energized.
Most instances ignore the OFF pole, however since your set up has 3 relays, I'm wondering if the third relay puts the fans in series, this would allow both fans to run at half speed.

[FElony]

Deleted

[Drew Pojedinec]

Appreciate your ramble Felony.  I picked up some good tidbits from it.

If I recall, I ran a 50amp fuse to the relays, than smaller ones after the relays.
Yes there is a temperature switch in the intake.  When I get back home, I'll look into why there is a third relay....  curious now.

My understanding of relays is a large wire running to a piece of equipment that is triggered by a smaller wire. 

[blykins]

That rear end is kinda epic......


I am kind of an electronics guy, wondering about the 3 relays...
As Jay pointed out, most of the "standard" or "unoversal" relays have 2 contacts, one provides a path for current when the relay is off, the other provides a path for current when the relay is energized.
Most instances ignore the OFF pole, however since your set up has 3 relays, I'm wondering if the third relay puts the fans in series, this would allow both fans to run at half speed.

The standard relay you refer to is a SPDT, or single pole double throw. This is a 5-lug which, as you say, outputs through the center position what is put into terminal 30 at rest, and outputs through the outboard terminal 87 when the coil is energized. There are 4-lug single pole single throws (SPST) which eliminate the center at rest output.

A relay as described with a 2x20 is a Double Pole Single Throw. They will typically have 87a and 87b marked terminals which both output from terminal 30 when closed (energized). There is no at rest output. They are used to provide power to two circuits which must remain separate from each other. Thus, it is best to place the fuse for each circuit after the outputs, so if one shorts it doesn't interrupt the power to the other.

DPST's are getting kind of scarce these days. We used to use them, in alarms, to flash the parking light circuits of European cars, as most of them had separate right and left hand circuits and were fused that way from the maker. Domestic and Japanese cars had both sides in one circuit, so a SPST or SPDT worked there. The original DPST Bosch relays were actually silver metal cased with a green diagonal stripe across the face.

Strange that Painless would use those. Technically, if those really are DPST, and they all trigger from a thermo switch, you would have 6 separate, isolated outputs rated at 20 amps apiece. Putting two 12v circuits in series would give you 24v, which would cause a 12v fan to turn twice as fast for a few moments until it burned up (unless the motor is rated to 24v). Paralleling two 12v circuits would double the amount of amperage capacity, staying at 12v.

There's a fair amount of tech involved in "properly" building aftermarket or upgraded factory circuitry. In my former career, I would burn through a couple 100-relay trays a month. I wrote tech papers and did seminars on the subject. When somebody applied for a job with me, I placed a relay on the desk and ask him to tell me how they actually worked. If they couldn't, then there was no second question.

These days, much of that tech can be found online. Some can't. OMG, I'm a relay Nazi.

I would pay to sit through one of your seminars.

"OK, shut up and listen you bunch of idiots...."

[shady]

I'll call bs. on the 24 volt theory. can't happen unless you have two independent 12v batteries in the car.

[cjshaker]

I'll call bs. on the 24 volt theory. can't happen unless you have two independent 12v batteries in the car.

Or a transformer, and not the robot kind.

[jayb]

I'll call bs. on the 24 volt theory. can't happen unless you have two independent 12v batteries in the car.

He did say putting two 12V circuits in series, so I assumed he was talking about two separate batteries.  Obviously can't happen with a single battery.

And Felony, although we all enjoy your pictures, there are plenty of other sites people can visit to see that sort of thing.  Not here, please...